It is planned that production of hydrochlorofluorocarbon (HCFC) is regulated due to its adverse effect on the ozone layer. Examples of HCFC include 3,3-dichloro-1,1,1,2,2-pentafluoropropane (HCFC-225ca), 1,3-dichloro-1,1,2,2,3-pentafluoropropane (HCFC-225cb), and so on. Development of a compound alternative thereto is demanded in accordance with the regulation of HCFC.
An example of the compound alternative to HCFC includes, for example, 1-chloro-2,3,3-trifluoropropene (HCFO-1233yd). HCFO-1233yd has a small global warming potential (GWP) and can be suitably used for uses in a cleaning agent, a solvent, a refrigerant, a foaming agent, aerosol, and so on.
There are a Z-isomer of HCFO-1233yd (HCFO-1233yd(Z)) and an E-isomer of HCFO-1233yd (HCFO-1233yd(E)) being structural isomers in HCFO-1233yd. HCFO-1233yd(Z) is mainly used for the uses in the cleaning agent, the solvent, the refrigerant, the foaming agent, and the aerosol.
International Publication No. 1994/14737 discloses a method for producing 1,1,2,2,3-pentafluoropropane (HCFC-245ca) from 1-chloro-2,2,3,3-tetrafluoropropane (HCFC-244ca) and hydrogen fluoride. Since HCFO-1233yd is secondary produced through this method, a composition containing HCFO-1233yd is obtained by separating HCFO-1233yd from a composition obtained by the above-stated method.
Though HCFO-1233yd generated by the above method is a mixture of HCFO-1233yd(E) and HCFO-1233yd(Z), it is preferable that each of HCFO-1233yd(Z) and HCFO-1233yd(E) can be used independently, and a composition of the mixture is adjustable depending on uses. However, International Publication No. 1994/14737 does not describe separation of HCFO-1233yd(E) and HCFO-1233yd(Z), and adjustment of the composition.
There is a case when water is mixed in during a production process of HCFO-1233yd. When water (moisture) is contained in the composition containing HCFO-1233yd(Z), reliability and performance may deteriorate when it is used as the cleaning agent, the solvent, the refrigerant, the foaming agent, or the aerosol to cause various problems. A content of water is preferably reduced as much as possible in order to avoid such an unfavorable influence.
In general, a by-product is removed from a reaction product through distillation by using a boiling point difference therebetween, but boiling points are close to one another such that the boiling point of HCFO-1233yd(Z) is about 54° C. and the boiling point of HCFO-1233yd(E) is about 48° C. It is therefore difficult to separate by means of a normal distillation column, and a method to more efficiently remove HCFO-1233yd(E) has been demanded.
Further, separation by means of distillation is difficult because a mixture of HCFO-1233yd(Z) and water forms an azeotropic-like composition, and a method to efficiently remove water has been demanded.